package lib;

import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;

/*
 *	Class to manage the widths of colunmns in a table.
 *
 *  Various properties control how the width of the column is calculated.
 *  Another property controls whether column width calculation should be dynamic.
 *  Finally, various Actions will be added to the table to allow the user
 *  to customize the functionality.
 *
 *  This class was designed to be used with tables that use an auto resize mode
 *  of AUTO_RESIZE_OFF. With all other modes you are constrained as the width
 *  of the columns must fit inside the table. So if you increase one column, one
 *  or more of the other columns must decrease. Because of this the resize mode
 *  of RESIZE_ALL_COLUMNS will work the best.
 */
public class TableColumnAdjuster implements PropertyChangeListener, TableModelListener {
    private JTable table;
    private int spacing;
    private boolean isColumnHeaderIncluded;
    private boolean isColumnDataIncluded;
    private boolean isOnlyAdjustLarger;
    private boolean isDynamicAdjustment;
    private Map<TableColumn, Integer> columnSizes = new HashMap<>();

    /*
     *  Specify the table and use default spacing
     */
    public TableColumnAdjuster(JTable table) {
        this(table, 6);
    }

    /*
     *  Specify the table and spacing
     */
    public TableColumnAdjuster(JTable table, int spacing) {
        this.table = table;
        this.spacing = spacing;
        setColumnHeaderIncluded(true);
        setColumnDataIncluded(true);
        setOnlyAdjustLarger(true);
        setDynamicAdjustment(false);
        installActions();
    }

    /*
     *  Adjust the widths of all the columns in the table
     */
    public void adjustColumns() {
        TableColumnModel tcm = table.getColumnModel();
        for (int i = 0; i < tcm.getColumnCount(); i++) {
            adjustColumn(i);
        }
    }

    /*
     *  Adjust the width of the specified column in the table
     */
    public void adjustColumn(final int column) {
        TableColumn tableColumn = table.getColumnModel().getColumn(column);
//        if (! tableColumn.getResizable()) return;
        int columnHeaderWidth = getColumnHeaderWidth(column);
        int columnDataWidth = getColumnDataWidth(column);
        int preferredWidth = Math.max(columnHeaderWidth, columnDataWidth);
        updateTableColumn(column, preferredWidth);
    }

    /*
     *  Calculated the width based on the column name
     */
    private int getColumnHeaderWidth(int column) {
        if (! isColumnHeaderIncluded) return 0;
        TableColumn tableColumn = table.getColumnModel().getColumn(column);
        Object value = tableColumn.getHeaderValue();
        TableCellRenderer renderer = tableColumn.getHeaderRenderer();
        if (renderer == null) {
            renderer = table.getTableHeader().getDefaultRenderer();
        }
        Component c = renderer.getTableCellRendererComponent(table, value, false, false, -1, column);
        return c.getPreferredSize().width;
    }

    /*
     *  Calculate the width based on the widest cell renderer for the
     *  given column.
     */
    private int getColumnDataWidth(int column) {
        if (! isColumnDataIncluded) return 0;
        int preferredWidth = 0;
        int maxWidth = table.getColumnModel().getColumn(column).getMaxWidth();
        for (int row = 0; row < table.getRowCount(); row++) {
            preferredWidth = Math.max(preferredWidth, getCellDataWidth(row, column));
            //  We've exceeded the maximum width, no need to check other rows
            if (preferredWidth >= maxWidth) break;
        }
        return preferredWidth;
    }

    /*
     *  Get the preferred width for the specified cell
     */
    private int getCellDataWidth(int row, int column) {
        //  Inovke the renderer for the cell to calculate the preferred width
        TableCellRenderer cellRenderer = table.getCellRenderer(row, column);
        Component c = table.prepareRenderer(cellRenderer, row, column);
        int width = c.getPreferredSize().width + table.getIntercellSpacing().width;
        return width;
    }

    /*
     *  Update the TableColumn with the newly calculated width
     */
    private void updateTableColumn(int column, int width) {
        final TableColumn tableColumn = table.getColumnModel().getColumn(column);
//        if (! tableColumn.getResizable()) return;
        width += spacing;
        //  Don't shrink the column width
        if (isOnlyAdjustLarger) {
                width = Math.max(width, tableColumn.getPreferredWidth());
        }
        columnSizes.put(tableColumn, new Integer(tableColumn.getWidth()));
        table.getTableHeader().setResizingColumn(tableColumn);
        tableColumn.setWidth(width);
    }

    /*
     *  Restore the widths of the columns in the table to its previous width
     */
    public void restoreColumns() {
        TableColumnModel tcm = table.getColumnModel();
        for (int i = 0; i < tcm.getColumnCount(); i++) {
            restoreColumn(i);
        }
    }

    /*
     *  Restore the width of the specified column to its previous width
     */
    private void restoreColumn(int column) {
        TableColumn tableColumn = table.getColumnModel().getColumn(column);
        Integer width = columnSizes.get(tableColumn);
        if (width != null) {
            table.getTableHeader().setResizingColumn(tableColumn);
            tableColumn.setWidth( width.intValue() );
        }
    }

    /*
     *	Indicates whether to include the header in the width calculation
     */
    public void setColumnHeaderIncluded(boolean isColumnHeaderIncluded) {
        this.isColumnHeaderIncluded = isColumnHeaderIncluded;
    }

    /*
     *	Indicates whether to include the model data in the width calculation
     */
    public void setColumnDataIncluded(boolean isColumnDataIncluded) {
        this.isColumnDataIncluded = isColumnDataIncluded;
    }

    /*
     *	Indicates whether columns can only be increased in size
     */
    public void setOnlyAdjustLarger(boolean isOnlyAdjustLarger) {
        this.isOnlyAdjustLarger = isOnlyAdjustLarger;
    }

    /*
     *  Indicate whether changes to the model should cause the width to be
     *  dynamically recalculated.
     */
    public void setDynamicAdjustment(boolean isDynamicAdjustment) {
        //  May need to add or remove the TableModelListener when changed
        if (this.isDynamicAdjustment != isDynamicAdjustment) {
            if (isDynamicAdjustment) {
                table.addPropertyChangeListener( this );
                table.getModel().addTableModelListener( this );
            } else {
                table.removePropertyChangeListener( this );
                table.getModel().removeTableModelListener( this );
            }
        }
        this.isDynamicAdjustment = isDynamicAdjustment;
    }
    
    /**
     * Implement the PropertyChangeListener
     * @param e 
     */
    @Override
    public void propertyChange(PropertyChangeEvent e) {
        //  When the TableModel changes we need to update the listeners
        //  and column widths
        if ("model".equals(e.getPropertyName())) {
            TableModel model = (TableModel)e.getOldValue();
            model.removeTableModelListener( this );
            model = (TableModel)e.getNewValue();
            model.addTableModelListener( this );
            adjustColumns();
        }
    }
    
    /**
     * Implement the TableModelListener
     * @param e 
     */
    @Override
    public void tableChanged(TableModelEvent e) {
        if (! isColumnDataIncluded) return;
        //  A cell has been updated
        if (e.getType() == TableModelEvent.UPDATE) {
            int column = table.convertColumnIndexToView(e.getColumn());
            //  Only need to worry about an increase in width for this cell
            if (isOnlyAdjustLarger) {
                int	row = e.getFirstRow();
                TableColumn tableColumn = table.getColumnModel().getColumn(column);
                if (tableColumn.getResizable()) {
                    int width =	getCellDataWidth(row, column);
                    updateTableColumn(column, width);
                }
            }
            //	Could be an increase of decrease so check all rows
            else {
                adjustColumn( column );
            }
        }
        //  The update affected more than one column so adjust all columns
        else {
                adjustColumns();
        }
    }

    /*
     *  Install Actions to give user control of certain functionality.
     */
    private void installActions() {
        installColumnAction(true, true, "adjustColumn", "control ADD");
        installColumnAction(false, true, "adjustColumns", "control shift ADD");
        installColumnAction(true, false, "restoreColumn", "control SUBTRACT");
        installColumnAction(false, false, "restoreColumns", "control shift SUBTRACT");
        installToggleAction(true, false, "toggleDynamic", "control MULTIPLY");
        installToggleAction(false, true, "toggleLarger", "control DIVIDE");
    }

    /*
     *  Update the input and action maps with a new ColumnAction
     */
    private void installColumnAction(boolean isSelectedColumn, boolean isAdjust, String key, String keyStroke) {
        Action action = new ColumnAction(isSelectedColumn, isAdjust);
        KeyStroke ks = KeyStroke.getKeyStroke( keyStroke );
        table.getInputMap().put(ks, key);
        table.getActionMap().put(key, action);
    }

    /*
     *  Update the input and action maps with new ToggleAction
     */
    private void installToggleAction(boolean isToggleDynamic, boolean isToggleLarger, String key, String keyStroke) {
        Action action = new ToggleAction(isToggleDynamic, isToggleLarger);
        KeyStroke ks = KeyStroke.getKeyStroke( keyStroke );
        table.getInputMap().put(ks, key);
        table.getActionMap().put(key, action);
    }

    /*
     *  Action to adjust or restore the width of a single column or all columns
     */
    class ColumnAction extends AbstractAction {
        
        private boolean isSelectedColumn;
        private boolean isAdjust;

        public ColumnAction(boolean isSelectedColumn, boolean isAdjust) {
            this.isSelectedColumn = isSelectedColumn;
            this.isAdjust = isAdjust;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            //  Handle selected column(s) width change actions
            if (isSelectedColumn) {
                int[] columns = table.getSelectedColumns();
                for (int i = 0; i < columns.length; i++) {
                    if (isAdjust)
                        adjustColumn(columns[i]);
                    else
                        restoreColumn(columns[i]);
                }
            } else {
                if (isAdjust)
                    adjustColumns();
                else
                    restoreColumns();
            }
        }
    }

    /*
     *  Toggle properties of the TableColumnAdjuster so the user can
     *  customize the functionality to their preferences
     */
    class ToggleAction extends AbstractAction {
            
        private boolean isToggleDynamic;
        private boolean isToggleLarger;

        public ToggleAction(boolean isToggleDynamic, boolean isToggleLarger) {
            this.isToggleDynamic = isToggleDynamic;
            this.isToggleLarger = isToggleLarger;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            if (isToggleDynamic) {
                setDynamicAdjustment(! isDynamicAdjustment);
                return;
            }
            if (isToggleLarger) {
                setOnlyAdjustLarger(! isOnlyAdjustLarger);
                return;
            }
        }
    }
}
